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Our laboratory is pursuing two research directions linked by creative approaches to microbiology. 

One part of our research group performs quantitative analyses of bacterial stress responses, in which we employ next-generation sequencing, single-molecule biophysical analyses, and biochemical techniques to determine the effects of stress-response enzymes on cellular organization and protection from cellular damage. 

The other part of the group uses interdisciplinary synthetic biology techniques to apply and re-engineer bacteria in order to produce improved, spatially-patterned biomaterials in an environmentally-friendly manner. We are among the first to combine synthetic biology with materials science, in order to produce sustainable structural materials inspired by seashells, 3D-printed living materials, conductive graphene materials, optical materials, and space materials.

1. Bacterial chromosome structure in response to changing environments
   Striking microscopy has revealed that under stressful conditions, bacterial DNA can condense into massive “biocrystals” with a high degree of order. These structures are created by the mini-ferritin Dps (DNA-binding protein in starved cells). Dps becomes the most abundant component of prokaryotic nucleoids in times of stress, driving massive remodeling of the bacterial chromosome and ensuring robust bacterial survival. Our lab is working to uncover the molecular mechanisms and physiological consequences of chromosome reorganization in bacterial cells.
2. Spatial patterning of microorganisms: 3D bacteria printing of engineered biofilms
   We have developed the first 3D printers for the deposition of bacteria. Our 3D bacteria printers are the cheapest bioprinters ever developed and can be easily constructed and implemented. The printers deposit bacteria within a supportive hydrogel with <mm-scale resolution, after which the bacteria can continue to survive and create desired products for days or weeks. We have developed 3D printing of E. coli bacteria that were engineered to produce biofilm extracellular matrix proteins. These engineered biofilms reproduce emergent properties of native biofilms including increased resistance to antibacterial treatments. These model biofilms will be crucial for development of anti-biofilm treatments, as well as for the development of beneficial engineered biofilms for applications such as water purification or mineral extraction.
3. Engineered living materials for bioplastic degradation in ocean environments
   Millions of tons of plastic waste enter the earth's oceans on a yearly basis. This plastic is destined to become long-lasting waste on the ocean floor or along coastlines. We are collaborating together with oceanographic roboticists and experimental oceanographers to design, test, and integrate 3D-printed microbes that can degrade plastics, in order to develop biomaterials designed to rapidly degrade at end-of-life in oceanic conditions.
4. Bacterial optical devices
   Brittlestar sponges are covered with an array of tightly packed micron-scale “bioglass” microlenses, produced by the silicatein enzyme, that far exceed manmade optical devices in terms of their light weight, small size, mechanical strength, and lack of aberrations and birefringence. We have fused sponge silicatein enzymes to E. coli outer membrane proteins in order to display these enzymes on the surface of bacterial cells. These engineered bacteria are able to mineralize a layer of glass on their cell surface, after which the living, glass-coated bacterial cell is able to capture and focus light. We are working to tune the mineralized glass layer chemistries and the bacteria cell shape in order to produce arrays of sustainably-produced ultra-thin and ultra-light-weight bacterial microlenses with tailored optical properties with applications in image capturing, surface defect inspection, and solar energy collection.
5. 3D-printed bacteria for clean energy production 
   The bacteria Shewanella is able to transfer electrons to environmental materials, a process which can be harnessed to create clean hydrogen fuel by introducing quantum dots as the electron acceptor. We are collaborating with electrochemistry laboratories to improve the efficiency of hydrogen gas production by engineering Shewanella bacteria with improved electron transfer activities. We are also 3D-printing Shewanella bacteria into complex three-dimensional structures that can carry out hydrogen production while protecting and conserving biomass.